Mobile de-roofing device and method for removing roofing material

ABSTRACT

A mobile de-roofing device operates to remove roofing material from a building. The de-roofing device includes a supporting frame and a plurality of wheels attached to the frame. A mechanical roof cutter is carried by the frame, and adapted for engaging the roofing material and separating the roofing material from a roof of the building. A remote power source is operatively connected to the roof cutter for supplying power from a remote location to actuate the roof cutter.

TECHNICAL FIELD AND BACKGROUND OF INVENTION

[0001] This application relates to a mobile de-roofing device and method for removing roofing material from a roof of a building. The invention is particularly applicable for commercial use on flat or low-sloped roof buildings in preparation for re-roofing. Typical commercial roofs are constructed of board type roof insulations. The roof membrane composite generally includes alternate layers of roofing felt and an asphalt base or tar base material. The final layer is typically a flood coat of asphalt or tar with gravel embedded into the bitumen. The top layer can also be a smooth surface.

[0002] Conventional prior art de-roofing devices simply cut small grooves into the roof composite, making squares of roofing material 1′×1′ or larger. These cut “squares” are then lifted and detached from the subsurface insulation, and are picked up either by hand or mechanical devices that drive under and collect the squares using inclined metal pans. The cut squares are placed into carts and transported to the edge of the roof where they are dumped into containers below. While generally effective, this practice is labor intensive, slow, and costly.

[0003] Another problem encountered in prior attempts to mechanically tear off and remove roofing material concerns the weight of the machinery on the roof. For most commercial flat roofs, 900 pounds is generally accepted as a maximum permissible concentrated load. In the course of testing the invention, it was discovered that power units necessary to attain an acceptable rate of tear-off required motors or engines that, in combination with fuel, transmission, etc., exceeded the weight limitation. The present invention addresses this problem by generating its power at a location remote from the actual device, thereby dramatically reducing the overall weight on the roof while providing substantially increased horsepower and production.

[0004] A further advantage of the invention over other mechanical de-roofers lies in the operation of its roof cutting element. Unlike many existing devices, the present invention separates the roofing material from the roof by first engaging the subsurface felt/tar layers of the composite and moving upwardly through the harder tar/asphalt-gravel layers. During operation of the device, the felt/tar temporarily adheres to the cutting element and protects the cutting element against wear and damage it would otherwise incur through direct contact with the asphalt-gravel.

SUMMARY OF INVENTION

[0005] Therefore, it is an object of the invention to provide a mobile de-roofing device which effectively and efficiently tears off an existing flat roof of a commercial building.

[0006] It is another object of the invention to provide a mobile de-roofing device which generates power at a location remote from the mechanical cutting element of the device.

[0007] It is another object of the invention to provide a mobile de-roofing device which requires relatively little weight located at the area being cut.

[0008] It is another object of the invention to provide a mobile de-roofing device which is highly productive.

[0009] It is another object of the invention to provide a mobile de-roofing device which is equipped to receive multiple attachments that facilitate transport of the roofing material from the roof to the ground.

[0010] It is another object of the invention is to provide a mobile de-roofing device that cuts the roofing material into fine segments that are easily transported off the roof for collection and disposal or recycling.

[0011] It is another object of the invention is to provide a mobile de-roofing device that cuts the roofing material into fine segments that are easily vacuumed.

[0012] It is another object of the invention is to provide a mobile de-roofing device which is either self propelled or propelled by another vehicle.

[0013] These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a mobile de-roofing device for removing roofing material from a building. The de-roofing device includes a supporting frame and a plurality of wheels attached to the frame. A mechanical roof cutter is carried by the frame, and adapted for engaging the roofing material and separating the roofing material from a roof of the building. A remote power source is operatively connected to the roof cutter for supplying power from a remote location to actuate the roof cutter.

[0014] The term “wheels” as used herein refers broadly to any low-friction or friction reducing means, including any rolling objects or sliding structure.

[0015] According to another preferred embodiment of the invention, the mechanical roof cutter includes a rotatable cutter drum mounted on an elongated drive shaft. The cutter drum includes a plurality of circumferentially-spaced cutter teeth adapted for engaging and cutting the roofing material.

[0016] According to another preferred embodiment of the invention, a belt drive assembly is operatively connected to the drive shaft of the cutter drum.

[0017] According to another preferred embodiment of the invention, a hydraulic motor is connected to the remote power source for actuating the belt drive assembly, thereby rotating the cutter drum.

[0018] According to another preferred embodiment of the invention, each of the cutter teeth has a recessed front face and equally spaced-apart and outwardly diverging cutting tips.

[0019] According to another preferred embodiment of the invention, each of the cutting tips has a generally triangular cutting surface defined by intersecting side edges.

[0020] According to another preferred embodiment of the invention, elevation adjustment means are provided for adjusting the elevation of the roof cutter relative to the roof. The de-roofing device is thus operable to remove only a predetermined thickness of roofing material from the roof.

[0021] According to another preferred embodiment of the invention, a material containment hood is mounted on the frame, and defines a collection zone for collecting and containing loose roofing material cut and separated from the roof by the roof cutter.

[0022] According to another preferred embodiment of the invention, a vacuum line is connected to the material containment hood and communicates with the collection zone for transferring cut roofing material from the roof to a distant area for disposal. Alternatively, the cut roofing material may be collected at the roof cutter and transported using a mechanical conveyor system and/or other conventional material handling equipment.

[0023] In another embodiment, the de-roofing device includes a supporting frame and a plurality of wheels attached to the frame. A mechanical roof cutter is carried by the frame, and includes a rotatable cutter drum and a plurality of circumferentially-spaced cutter teeth. The cutter teeth are adapted for engaging the roofing material and separating the roofing material from a roof of the building. A remote power source is operatively connected to the roof cutter for supplying power to actuate the rotatable cutter drum. The power source is located a remote distance from the roof of the building. A material containment hood is mounted on the frame, and defines a collection zone for collecting and containing loose roofing material cut and separated from the roof by the roof cutter.

[0024] According to another preferred embodiment of the invention, the plurality of wheels comprises at least two rear drive wheels and a front guide wheel.

[0025] According to another preferred embodiment of the invention, elevation adjustment means are connected to the rear drive wheels for adjusting the elevation of the roof cutter relative to the roof. The de-roofing device thus operates to separate and remove only a predetermined thickness of roofing material from the roof.

[0026] According to another preferred embodiment of the invention, the elevation adjustment means includes respective cylinders operatively connected to the rear drive wheels to independently adjust the position of the rear wheels relative to the cutter drum.

[0027] According to another preferred embodiment of the invention, the front guide wheel is swivel attached for 360 degree swivel movement.

[0028] According to another preferred embodiment of the invention, first and second depth control skids are attached to the frame and operate to define a maximum cutting depth of the roof cutter.

[0029] In yet another embodiment, the invention is a method of separating roofing material from a roof of a building. The method includes the steps of penetrating the roofing material with a first cut through a top surface of the roofing material. A second cut of the roofing material is then created downstream of the first cut. The second cut starts from a predetermined subsurface depth and penetrates upwardly towards the top surface of the roofing material.

[0030] According to another preferred embodiment of the invention, the step of penetrating the roofing material includes actuating a mechanical roof cutter of a de-roofing device located on the roof of the building. The roof cutter includes a plurality of cutter teeth adapted for engaging the roofing material and separating the roofing material from the roof.

[0031] According to another preferred embodiment of the invention, the step of creating a second cut through the roofing material includes moving the cutter teeth into and through the roofing material from the subsurface depth upwardly towards the top surface, such that the subsurface roofing material engages and protests the cutter teeth as the cutter teeth separate the roofing material from the roof.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Some of the objects of the invention have been set forth above. Other objects and advantages of the invention will appear as the description proceeds when taken in conjunction with the following drawings, in which:

[0033]FIG. 1 is an environmental perspective view of the mobile de-roofing device according to one preferred embodiment of the invention, and showing the device on the roof of a building with the remote power unit located on the ground adjacent to the building;

[0034]FIG. 2 is a rear perspective view of the de-roofing device, and showing particularly the drive belt assembly operable for actuating the cutter drum;

[0035]FIG. 3 is a front perspective view of the de-roofing device, and showing particularly the front containment hood and vacuum attachment for collecting and transporting cut roofing material from the roof to a remote disposal site;

[0036]FIG. 4 is a further rear perspective view of the de-roofing device, and showings particularly the connection of the hydraulic supply and return lines and the vacuum line to the device;

[0037]FIG. 5 is front perspective view of the de-roofing device with certain elements removed to more clearly illustrate the cutter drum and teeth; and

[0038]FIG. 6 is a side elevation of the de-roofing device with elements removed and showing a portion of the roofing material in cross-section to illustrate the interaction of the teeth with the roofing material during operation of the device.

DESCRIPTION OF THE PREFERRED EMBODIMENT AND BEST MODE

[0039] Referring now specifically to the drawings, a mobile de-roofing device according to the present invention is illustrated in FIG. 1, and shown generally at reference numeral 10. The de-roofing device 10 is especially applicable for commercial use on flat top buildings “B” (or those with low-sloping roofs) for separating and removing the existing roof “R” in preparation for re-roofing. Typical commercial, large-area roofs are constructed of a 1-3 inch material composite (See FIG. 6) including bottom felt layers 11 positioned over roofing insulation 12, intermediate tar layers 14 between the felt layers, and a top asphalt-gravel layer 15 imbedded in the tar. To minimize the load on the roof “R”, the de-roofing device 10 utilizes a remote power generation source 16 located on the ground adjacent to the building “B”. According to one embodiment, the power source 16 is a hydraulic power unit including separate supply and return lines 18 and 19 connected to the de-roofing device 10. During operation of the de-roofing device 10, the loose cut roofing material is preferably transported off of the roof “R” through a vacuum hose 21 connected to the de-roofing device 10 and a pneumatic blower (not shown). Alternatively, the cut roofing material may be transported using a mechanical conveyor system and/or other conventional material handling equipment.

[0040] As shown in FIGS. 2, 3, and 4, the de-roofing device 10 includes a supporting frame 22, a pair of rear drive wheels 23 and 24, and a front guide wheel 25. The rear wheels 23,24 travel, respectively, on cut and uncut areas of the roof “R”. In order to compensate for the 1-2 inch elevation difference and thereby maintain a uniform cutting depth, the rear wheels 23, 24 are vertically adjustable independent of one another to control their respective positions relative to the frame 22. Hydraulic cylinders 26 and 27 connected to the supply and return lines 18,19 operate to raise and lower each of the rear wheels 23, 24. The hydraulic cylinders 26, 27 are preferably actuated by user control levers 28 and 29 attached to a steering arm 31. The front guide wheel 25 is swivel attached to facilitate maneuvering the device 10 on the roof “R”.

[0041] The supporting frame 22 carries a mechanical roof cutter 35 best shown in FIGS. 5 and 6. The roof cutter 35 includes a rotatable cutter drum 36 mounted on a drive shaft 37, and having a number of circumferentially-spaced cutter teeth 38 located on an outer periphery of the drum 36. The drive shaft 37 is actuated by a drive belt assembly 40 including a belt 41 and cooperating rollers 42 and 43 connected to the drive shaft 37 and a motor shaft 44, respectively. The motor shaft 44 is powered by a hydraulic motor 45 connected through the supply and return lines 18, 19 to the hydraulic power source 16. Operation of the motor shaft 44 causes rotation of the drive belt assembly 40 and cutter drum 36. Preferably, the hydraulic motor 45 generates a minimum of 40 HP at the motor—shaft 44 effecting drum speeds as high as 800 RPM. The power generated is sufficient to cut and remove a 20-inch wide section of roof “R” at 10 feet per 20 seconds. Control lever 48 controls operation of the motor shaft 44 and the resulting speed of the drum 36.

[0042] The cutter teeth 38 are attached to holders 49, and are preferably removable and replaceable when worn. Each tooth 38 has an recessed front face and four equally spaced and outwardly-diverging cutting tips 51. Each of the cutting tips 51 has a generally triangular cutting surface formed by respective pairs of intersecting side edges. Preferably, the side edges of each pair diverge from each other at an angle of approximately 60 degrees and extend inwardly in a direction towards the rear of the tooth 38. Because the cutting tips 51 are subject to wear over a period of use, the cutter tooth 38 can be periodically rotated, or indexed, in order to maintain fresh cutting tips 51 in the cutting position during operation of the device 10. An example of a cutter tooth 38 applicable to the present invention is described in U.S. Pat. No. 5,205,199 issued to Quadco Equipment, Inc. The complete disclosure of this patent is incorporated herein by reference.

[0043] Operation of the cutter drum 36 and cutter teeth 38 is best illustrated in FIG. 6. The rear drive wheels 23, 24 propel the de-roofing device 10 forward simultaneously during cutting. Upon rotation of the cutter drum 36, as indicated at 52, and after an initial cut through the top surface of the roof “R”, the two outside cutting tips 51 of each tooth 38 first contact the subsurface felt/tar layers 11, 14 of the roofing material before accelerating upwardly through the tar/asphalt-gravel layers 14, 15. This cutting technique substantial reduces vibration of the device 10, as' compared to other devices which drive cutting elements directly into the asphalt-gravel layer of the roofing material. In addition, because the cutter tooth 38 makes first contact with the felt/tar layers 11,14, these layers will temporarily adhere to the face of the tooth 38 and protect the cutting tips 51 from excessive wear and damage caused by the asphalt-gravel 15 during de-roofing. Because of the orientation of the cutting tips 51, a thin planar cut is made through the roofing material without penetrating or otherwise damaging the underlying insulation 12. The plurality of teeth cooperate to cut the roofing material into small pieces, generally 2 inches or less in length.

[0044] Preferably, the de-roofing device 10 includes depth control skids 55 and 56 which serve as a safety to prevent the cutter drum 36 from tearing through the subsurface insulation 12 (or roof decking) should the rear wheels 23, 24 inadvertently drop or sink downwardly through the roof “R”. The depth control skids 55, 56 are vertically adjusted by threaded pins 58 with respective manual turn wheels 59.

[0045] After cutting, the loose roofing material is immediately discharged into a collection zone defined by a material containment hood 61, shown in FIG. 3, located forward of the cutting drum 36. In the collection zone, the cut roofing material is deflected downwardly onto a drop plate 62 shown in FIG. 5. The vacuum hose 21 communicates with the collection zone to suction and transport the material from the drop plate 62 off the roof “R” and into a waste container (not shown) located on the ground. In an alternative embodiment, the cut roofing material is transported from the de-roofing device via a conveyor system including material carriers which receive the material from the collection zone and transport it to the edge of the roof for dumping.

[0046] A mobile de-roofing device is described above. Various details of the invention may be changed without departing from its scope. Furthermore, the foregoing description of the preferred embodiment of the invention and best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the claims. 

We claim:
 1. A mobile de-roofing device for removing roofing material from a building, said deroofing device comprising: (a) a supporting frame; (b) a plurality of wheels attached to said frame; (c) a mechanical roof cutter carried by said frame, and adapted for engaging the roofing material and separating the roofing material from a roof of the building; and (d) a remote power source operatively connected to said roof cutterfor supplying power from a remote location to actuate said roof cutter.
 2. A mobile de-roofing device according to claim 1, wherein said mechanical roof cutter comprises a rotatable cutter drum mounted on an elongated drive shaft, and including a plurality of circumferentially-spaced cutter teeth adapted for engaging and cutting the roofing material.
 3. A mobile de-roofing device according to claim 2, and comprising a belt drive assembly operatively connected to the drive shaft of said cutter drum.
 4. A mobile de-roofing device according to claim 3, and comprising a hydraulic motor connected to said remote power source for actuating said belt drive assembly, thereby rotating said cutter drum.
 5. A mobile de-roofing device according to claim 1, wherein each of said cutter teeth comprises a recessed front face and equally spaced-apart and outwardly diverging cutting tips.
 6. A mobile de-roofing device according to claim 5, wherein each of said cutting tips has a generally triangular cutting surface defined by intersecting side edges.
 7. A mobile de-roofing device according to claim 1, and comprising elevation adjustment means for adjusting the elevation of said roof cutter relative to the roof, whereby said de-roofing device is operable to remove only a predetermined thickness of roofing material from the roof.
 8. A mobile de-roofing device according to claim 1, and comprising a material containment hood mounted on said frame and defining a collection zone for collecting and containing loose roofing material cut and separated from the roof by said roof cutter.
 9. A mobile de-roofing device according to claim 8, and comprising a vacuum line connected to said material containment hood and communicating with said collection zone for transferring cut roofing material from the roof to a distant area for disposal.
 10. A mobile de-roofing device for removing roofing material from a building, said de-roofing device comprising: (a) a supporting frame; (b) a plurality of wheels attached to said frame; (c) a mechanical roof cutter carried by said frame, and comprising a rotatable cutter drum and a plurality of circumferentially-spaced cutter teeth, said cutter teeth adapted for engaging the roofing material and separating the roofing material from a roof of the building; (d) a remote power source operatively connected to said roof cutter for supplying power to actuate said rotatable cutter drum, said power source being located a remote distance from the roof of the building; and (e) a material containment hood mounted on said frame and defining a collection zone for collecting and containing loose roofing material cut and separated from the roof by said roof cutter.
 11. A mobile de-roofing device according to claim 10, wherein said plurality of wheels comprises at least two rear drive wheels and a front guide wheel.
 12. A mobile de-roofing device according to claim 11, and comprising elevation adjustment means connected to said rear drive wheels for adjusting the elevation of said roof cutter relative to the roof, whereby said de-roofing device operates to separate and remove only a predetermined thickness of roofing material from the roof.
 13. A mobile de-roofing device according to claim 12, wherein said elevation adjustment means comprises respective cylinders operatively connected to said rear drive wheels to independently adjust the position of said rear wheels relative to said cutter drum.
 14. A mobile de-roofing device according to claim 10, wherein the front guide wheel is swivel attached for 360 degree swivel movement.
 15. A mobile de-roofing device according to claim 10, and comprising first and second depth control skids attached to said frame and operating to define a maximum cutting depth of said roof cutter.
 16. A mobile de-roofing device according to claim 10, and comprising a vacuum line connected to said material containment hood and communicating with said collection zone for transferring cut roofing material from the roof to a distant area for disposal.
 17. A mobile de-roofing device according to claim 10, wherein each of said cutter teeth comprises a recessed front face and equally spaced-apart and outwardly diverging cutting tips.
 18. A method of separating roofing material from a roof of a building, said method comprising the steps of: (a) penetrating the roofing material with a first cut through a top surface of the roofing material; and (b) creating a second cut of the roofing material downstream of the first cut, the second cut starting from a predetermined subsurface depth and penetrating upwardly towards the top surface of the roofing material.
 19. A method according to claim 18, wherein the step of penetrating the roofing material comprises actuating a mechanical roof cutter of a de-roofing device located on the roof of the building, the roof cutter comprising a plurality of cutter teeth adapted for engaging the roofing material and separating the roofing material from the roof.
 20. A method according to claim 19, wherein the step of creating a second cut through the roofing material comprises moving the cutter teeth into and through the roofing material from the subsurface depth upwardly towards the top surface, such that the subsurface roofing material engages and protects the cutter teeth as the cutter teeth separate the roofing material from the roof. 